Sheet separating mechanism



F. E. CURTIS SHEET SEPARATING MECHANISM Original Filed Feb. 8. 1941 .3Sheets-Sheet 1 Aug. 1 s, 1942.

ori inal Filed Feb. 8. v194,1

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-gala fiwnz $72 ATTORNEYS Aug 1 1942. F. E. CURTIS- SHEET SEPARATINGMECHANISM Original Filed Feb. 8, 1941 3 Sheets-Sheet 3 INVENTOR.FPfl/VKL/N ,5. Cuzr/s Patented Aug. 18, 1942 smmr ssmmrmemeonmrsmFranklin E. Curtis, Willou Addressograph-Multi 37 0,834. Divided ghby,Ohio, asslgnor to graph Corporation, Cleveland, Ohio, acorporationofDelaware Original application February a, 1941, Serial No.

1941, Serial No. 393,209

13 Claims. (oi. 2 71-2s) This invention relates to improvements in sheetseparating and feeding mechanisms and is a division of my copendingapplication for Sheet feeding mechanism, filed February 8, 1941, andassigned Serial No. 370,834. Thepresent invention is particularlyconcerned with a sheet separating and feeding mechanism which withdrawssheets one at a time from the top of a stack or pile of sheets and feedsthem to another mechanism.

The general object of the present invention is to provide an improvedsheet separating and feed ing mechanism which will separate and withdrawsheets one at a time from a stack or pile of sheets and deliver them toand in timed relationship with another mechanism, such asa printingmachine.

A more specific object of the present invention to provide an improvedpneumatic sheet separating mechanism for removing sheets one at a timefrom the top of a'stack of sheets and feeding the separated sheet intoanother mechanism, as for instance, a pair of coacting feed rolls whichMounted on the frame at of work sheets supported on a complete theremoval of thesheet from the stack.

Another object of the present invention is to provide animproved sheetseparating mechanism, which will effectively separate and remove sheetsone at a time from the top of a stack of sheets at a relatively highrate of speed.

Other objects and features of this invention will become moreapparentfrom the following description, reference being had to theaccompanying drawings'in which there is illustrated a preferredembodiment of the invention. The essential features of the inventionwill be summarized in the claims.

In the drawings, Fig. 1 is aside elevationof a duplicating machine inwhich the sheet separating and feeding mechanism of the presentinvention is incorporated, the entire mechanism being mounted in acommon cabinet, a part of Whichhas been broken away to illustratecertain power operating mechanism; Fig. 2 is an enlarged side elevationof the sheet separating and feeding mechanism with certain moved; Fig. 3is a plan view of the mechanism shown in Fig. 2; Fig. 4 is an enlargedsectional view of the sheet separating and feeding mechanism, the planeof the section being indicated by the lines 44 on Fig. 3; Fig.5 is anenlarged detail of the pneumatic sheet separating member and certainassociated mechanism; Fig. 6 is a fragmentary elevation of theseparating unit as viewed from the far side of Fig. 1-, and Fig. 7 is asectional detail as indicated by the lines 1-1 on Fig. 6.

Referring now to the drawings, wherein there is illustrated a preferredformof the invention,

and particularly to Fig. 1, there is shown a frame [0 enclosed by acabinet II which is provided with cover plates 'reand this applicationMay 13,

the interior thereof. the upper left hand end as viewed in Fig. 1, is aprinting machine l4. At the right hand end of the cabinet there is astack or pile support l5, which supports a stack doors l2 to permitaccess to a time to the printing machine. Atop the cabinet, adjacent thepile support, is the sheet sepa-' rating device It with which thepresent invention is particularly concerned and which separates thetop'sheet from the pile and progresses it to a delivery-table and sheetfeeding mechanism interposed between the separating device and theprinting mechanism. The delivery table and feeding mechanism is notillustrated in detail. However, reference may be had to my copendingapplication heretofore mentioned, for a complete description of suchmechanism.

The printing machine shown is a planographic duplicating machine. It ispair of cross bars 25 of the frame In, and comprises a; pattern roll 26,an offset roll 21, a platen roll 28, and an inking mecha- 'nism (notshown). The various rolls of the printing machine are journalled insuitable side plates, one of which is shown at 29 in Fig. 1.

The printing mechanism is driven by a motor 30 mounted on a bracket 3|disposed within the cabinet ll. Suitable driving elements, includingbelts and pulleys 32 interconnect the motor 30 with a gear 33, whichmeshes with a gear 34 carried by the offset roll 21, thus driving thelatter. The pattern roll 26 is driven by frictional engagement with theoffset roll in the usual manner. The platen roll is driven by a gear 35carried thereby and which meshes with the gear 34.

The paper table l5 which supports the pile or stack of sheets W to befed, is best illustrated in Figs. 1, 3, and 4. As there shown, the stackof on a table 40, with its forward corners seated in verticallyextending guides M, which are adjustable transversely of frame members42. The paper table 40 is slidably mounted for vertical movement in theframe Ill. The table 40 may be raised at periodic intervals to maintainthe uppermost sheet in the stack substantially in a predetermined planewhere it may be conveniently engaged by the sheet separating mechanismI6 hereinafter to be more fully described.

As-illustrated in Figs. 1 and 4, the paper table 40 is provided with apair of side flanges 46, each of which carries a pair of rollers 41.These rollers project outwardly from the sides of the table 40 andengage the flanges of vertically extending channels 48 carried by theframe l0 thus guiding the table for vertical movement.

W to be separated and fed one at in the drawings supported by a pair ofchains, I

. raised whenever the top of the stak drops below a predetermined level.A preferred form of power operated mechanism and a control therefor toperiodically raise the table 40 is shown and described in my copendingapplication heretofore referred to. l

The sheet separating mechanism with which the present invention is.particularly concerned will now be described. The top sheet in the stackW is separated from the rest of the stack and fed to a pair of feedmembers 5| and 52 by a suction foot 50. This foot is first moved into.contact with the uppermost sheet in the stack.

Suction is then applied to the foot causing the contacted sheet toadhere thereto. The foot is then raised to separate the forward portionof the top sheet from the remaining sheets in the stack. The foot isthen moved forward completing the separation of the sheet and carryingit forward into the bite of the feed rolls 60 and 5| which are disposedforward of the stack as indicated in Fig. 5. As the foot inserts thesheet in the bite of the rolls 6|, 52, the suction is removed releasingthe sheet, whereupon the rolls complete the removal of the sheet fromthe stack. As the rolls withdraw the sheet, the suction foot movesrearwardly and begins to move toward the top of the stack to startanother cycle of operation.

The suction foot 60 comprises a hollow casting, the lower end 64 ofwhich is open, and the upper end of which is connected by a flexibleconduit 55 and other means hereinafter to be described to a vacuum pump90. The foot 60 is adjustably secured to a shaft 55 by a set screw 61 tofacilitate adjustment transversely I of the feeding mechanism.

The suction foot is operated in timed relation with the printingmachine. As illustrated in Figs. 3 and 4, the shaft 55 carrying thesuction foot is journalled at its ends in a pair of arms 53 which aresecured to a cross shaft 68 rotatably mounted in the side plates 51. Asillustrated in Figs. 2 and 3, the shaft 65 has secured to its outer enda lever 59, the lower end of which has a pin and slot connection with abar 1| pivotally connected, as at 12, to the upper end of a lever l1.This lever is pivoted at l8 to a frame plate 51 of the separatingmechanism, and is connected by a link I9 with a crank arm 20 of theprinting machine. The crank 20, as illustrated in Fig. 1, is mounted ona shaft 2| of the printing machine and is drivingly connected by gearing22 with the platen roll gear 35 heretofore described. Thus the lever I1is rocked in timed relation to the rotation of the platen roll. Therelationship illustrated is such that the lever l1 operates once duringeach revolution of the platen roll.

The periodic rocking of the lever 11 above described results in therocking of the shaft 58 and imparts an up-and-down movement to thefoot-carrying shaft 55. As heretofore mentioned, the suction foot firstraises, and then swings forward to move the sheet to the bite of thefeed rolls 5|, and 52. This operation and movement is best illustratedin Fig. 5. As there showman arm 15 is secured to the foot-carrying shaft55 .and is provided at its lower end with a roller 15 which is drawn bya spring 15 into engagement with a guide block 11 secured to a sideplate 51. This guide block (Fig. 5) inclines upwardly and rearwardly sothat as the shaft 58 and arms 53 rock in a clockwise direction (Fig. 5),the lower end of the suction foot moves upward, substantiallyvertically, as indicated by the progressive series of dotted lines 19.When the foot'50 reaches the position indicated by the uppermost ofthese lines, a second roller 80, carried by the arm 15 is engaged by anadjustable but relatively stationary abutment 8|. Continued rocking ofthe parts about the axis of the shaft 58 then causes the suction foot 50to swing in a clockwise direction about the moving axis of the shaft 55,moving the foot toward the bite of the feeding rolls as indicated by theseries of dotted lines 82. This movement of the suction foot hasbeenfound to be highly efficient in separating the top sheet from thestack and enables the feeding of sheets of various thicknesses atrelatively high speeds.

Another feature of the present invention which assists in the separationof the sheets is shown in Figs. 4 and 5. At the front of the stack ofsheets W, there is a transversely extending frame bar 42 heretoforementioned. Adjustably mounted on this bar and extending over the frontedge of the stack is one or more flat spring fingers 86. These fingersare each adjustably positioned on the bar by adjusting screw 88 and arenormally spaced 9. predetermined distanec above the uppermost sheet W ofthe stack and above the lowermost position of the sheet engaging surface5| of the suction foot. It will be noted from Fig. 5, that these springfingers project inwardly above the stack a comparatively short distance,hence, as the suction foot raises a sheet W from the stack, theinnermost end of the sheet is drawn with a wiping motion past the end ofthe finger. Should two or more sheets tend to raise with the suctionfoot, this wiping movement generally causes all but the top sheet toreturn to the stack.

A combined motor driven pump 90 provides the suction supply for the foot60. This pump is best illustrated in Fig. 1, and as there shown, ismounted within the cabinet II on a cross frame member of the frame ID. Amotor 9|, also mounted within the cabinet II, is drivingly connectedwith the sump by a driving belt 92. The suction side of the pump 90 isconnected with a filter 93 which in turn is connected with a valve 95 bya conduit 94. The valve is connected with the suction foot by a flexibleconduit 55 heretofore described.

The pressure side of the pump 90 is connected by a pair of conduits H5to respective jets H0 disposed at opposite sides of the stack of sheets.As shown in Figs. 1, 3, and 4, these jets direct air under pressuretoward the sides of the uppermost sheets in the stack. The jets arepositioned adjacent the forward edges of the stack and direct blasts ofair beneath the forward portion of each sheet while it is beinglifted'by the suction foot.

The suction to the foot 50 is controlled by and causing the sheet tosuction foot.

prises a valve body having a through passageway 06, the opposite ends ofwhich are in communication with the conduits 65 and 04, respectively.Intermediate its ends the valve body is provided with a port 01, whichwhen closed, brings the suction side of the pump into-directcommunication with the suction foot 00. However, when this port, isopened, the suction to the foot is broken by atmospheric, pressureentering the port.

The valve port 91 is opened and closed in timed relationship with theoperation of the suction foot 60. .Pivoted to the bodyof the valve 95 isa lever 08 which carries a closurev 99 for the port 91. A spring Inormally retains the closure seated against the valve port. .In Fig. 4,the parts are shown in the positions theyassume immediatelyafter theclosing of the valve port to apply suction to the foot 60. It will beremembered that the foot is raised and swung forward by the clockwiserotation of theshaft 60. Secured to thisshaft is a lever IOI having aninwardly extending portion I02 which carrles an adjustable screw I03 anda contactor I04. As the shaft 60 swings to cause a sheet to be fed, thelever IOI swings toward the upper end of the valve lever 98 and as thefeed rolls BI and '62 are about to grip the sheet, the screw I03contacts the lever 00 opening the port 01 When the valve closure lever90 moves to open the valve port, a pin I05 carried thereby en'- gagesand cams upward one arm of a bell crank A spring I 01, interposedbetween the bell crank and a frame plate 51 then causes a latch portionI00 of the bell crank to engage the pin I05 and retain the valve closu 0in an open position. On the return stroke of the foot 60, the swingingof the shaft 08 in a counterclockwise direction causes the contractorI04 of the lever IM to engage an adjustable screw I09 on the upper armof the bell crank I06 and move the latch portion thereof out ofengagement with the port closure lever 98, closing the port andreturning the parts to the position illustrated in Fig. 4.

The adjustability of the screw I03 which coacts with the lever 98 toopen the port 91 of the valve 95 to relieve the pressure in the vacuumline 65 enables the release of the sheet W from the foot 60 to beaccurately timed. By adjusting the timing of this releasing action andby controlling the forward limit of movement of the suction foot throughthe adjustment of the abutment 8| heretofore described, the mechanismmay be adjusted to feed sheets at a relatively high rate of speed.

As under normal conditions it is desirable to feed a sheet with eachrevolution of the print-.

ing machine rolls, an arragement is provided to cause the sheetseparating mechanism to become effective to separate a sheet from thestack either every revolution of the printing rolls or alternaterevolutions as desired. This is preferably accomplished by controllingthe operation of the suction relief valve 99.

As illustrated in Figs. 6 and 7, the suction relief valve 99 iscontrolled to render the feeding mechanism effective on alternate cyclesof operation only, by a device which latches the valve-open every othercycle of operation of the mechanism and thus permits the removal of asheet W from the stack of sheets only on alternate cycles of operationof the suction foot 60.

be released from the '3 As heretofore described, the arm 'IOI makesonecomplete oscillation in each cycle of operation of the feedingmechanism. A link I is pivotally interconnected between the arm IOI anda I2I which is pivoted on a shaft I22 pawl carrier carried by theadjacent frame plate 51. A pawl I 23, pivoted to the carrier I2I in theusual manner, engages a ratchet wheel I 24 the latter a distance of onetooth during each cycle of operation.

The intermittent advancement of the ratchet wheel controls the movementof the valve lever 08. Secured to the ratchet wheel I 24 is a cam discI25 having high points I26 and low points I21. Secured to the valvelever is a roller I28 which is drawn toward the cam disc by the valvelever closing spring I 00 heretofore described. The cam disc is soarranged that when a high point I26 contacts the roller I28, the valvelever I will be retained in an open position, and when a low point I 2'!lies opposite the roller I28, the spring I00 will move the lever into avalve closing position. In the embodiment illustrated, the high and lowpoints of the cam are alternately arranged and are of such a nature asto permit the valve 09 to be closed only on alternate cycles ofoperation. This renders the sheet feed inefiective without disturbingthemovement of the parts.

I claim:

'1. In a sheet feeding mechanism, a frame, a pair of feeding rollscarried by said frame, a support for a stack of sheets to be fed, asheet separator, a member pivoted at one end relative to said frame andpivotally supporting said separator at its other end, said member tomove said away from the top of a stack, on said separator after it haspredetermined distance to swing said separator toward said rolls.

2. In a sheet feeding mechanism, a frame, a pair of feeding rollscarried by said frame, a support for a stack of sheets to be fed, asheet separator, an oscillatable member pivoted at one end relative tosaid frame and pivotally supporting said separator at its other end,means to resiliently retain said separator in a predetermined positionrelative to said member, means to swing said member to substantiallyupward away stack, and means acting on it has moved upward apredetermined distance to swing said separator toward said rolls.

3. In a blank separating mechanism, a frame, a pair of coacting feedrolls mounted in said separator upward and means acting frame, means tosupport a stack of superposed swing said member, and an adjustableabutment adapted and arranged in the path of said separator to swing theseparator about its pivotal connection with said member.

4. In a blank separating mechanism, a frame, 'a pair of coacting feedrolls mounted in said frame, means to support a stack'of superposedsheets, a member oscillatable about a fixed axis relative to said frame,a sheet separator pivotally connected at one. end to said member at apoint spaced from said axis, resilient means to retain said separatornormally in a position depending and advances means to oscillate movedupward a' move said separator from the top of a. said separator aftertoward the stack of sheets, means to swing said member to move saidseparator toward and away from said stack, means coacting with saidseparator to cause it to move substantially vertically during the firstportion of the raising movement, and an adjustable abutment adapted andarranged to coact with said separator during a subsequent portion of itsraising movement to swing the separator toward said rolls.

5. In a sheet feeding mechanism, a frame, a pair of feeding roll'scarried by said frame, a support for a stack of sheets to be fed, apivoted arm, a sheet separating member pivotally mounted on said arm,means -to rock said arm and member as a unit to move said separatingmember substantially upward away from said stack, and means acting onsaid member after it has been moved upward a predetermined distance toswing said member about itspivotal connection with said arm consequentupon the continued rocking of said arm and thereby move said memberforward toward said feeding rolls.

6. In a sheet feeding mechanism, a frame, a pair of sheet feeding rollscarried by the frame, a support for a stack of sheets to be fed, asuction sheet separating foot adapted to engage and raise the top sheetof said stack, a movable memberto which said foot is pivoted, a rolleron an axis rigid with said foot, a guide engaged by said roller, aspring tending to keep the roller in contact with the guide, and anabutment adapted to be engaged by means rigid with the foot and back ofthe pivot thereof, whereby as said member moves upwardly the foot maymove upwardly under the control of said guide until said abutment isengaged after which the continued upward movement of the member swingsthe foot toward the pair of sheet feeding rolls.

7. In a sheet feeding mechanism, a frame, a pair of feeding rollscarried by said frame, a sup- ;port for a stack of sheets to be fed, asheet separating member, a bar on which said separating member issecured, a pair of arms each of which is pivotally connected at one endto said frame,

said bar being journailed in the other end of said arms, a crank armsecured to said bar, a guide carried by said frame, means to resilientlyretain the crank arm in contact with said guide and cause saidseparating member to move upward away from said stack consequent uponthe rocking of said arms about their pivotal connection, and meansacting on said crank arm after said foot has moved upward apredetermined distance to swing said crank arm and separating memberabout the axis of said bar consequent upon the continued rocking of saidarms.

8. In a sheet feeding mechanism, a frame, a pair of sheet feeding rollscarried by said frame, a support for a stack of sheets to be fed, asuction sheet separating foot adapted to engage and raise the top sheetof said stack, a bar to which said foot is secured, a shaft journalledin said frame, a pair of spaced arms each of which is secured at one endto said shaft, said bar being journalled in the other end of said arms,a plate secured to said bar, a roller carried by said plate, a camcarried by said frame, a resilient means to retain the roller in contactwith said cam to cause said foot to move substantially upward away fromsaid stack consequent upon the rocking of said shaft, and an abutmentadapted and arranged to engage said plate after said foot has movedupward a predetermined distance to swing said plate and foot about theaxis of said bar against the action of said resilient means andconsequent upon continued rocking of said shaft to move the raised sheetforward into the bite of said rolls.

9. In a. sheet separating mechanism, a pair of feed rolls, a support fora stack of sheets, a suction device movable between said stack and saidrolls, a source of vacuum pressure, a connection between said source andsaid suction device, means to adjustably control the time of applicationand release of vacuum to said device, and adjustable means to limit themovement of said device toward said rolls.

10. In a sheet separating mechanism, a pair of feed rolls, disposed oneabove the other, means to support a stack of sheets with the uppermostsheet in a plane normal to a plane passing through the axes of saidrolls and below the bite thereof, a suction device movable in asubstantially vertical direction to and from said stack and in atransverse direction toward and away from said rolls, a source of vacuumpressure, a connection between said source and said suction device, avalve to control the application and release of vacuum to said device,and adjustable. means .to operate said valve and means to adjustablylimit the movement of said device toward said rolls.

11. In a sheet feeding mechanism, a support for a stack of sheets, asuction foot suspended above the stack, means to move said foot intocontact with the top sheet in the stack, suction producing means, asuction relief valve, means to move said foot and a sheet adheringthereto away from said stack, means connected with said foot to opensaid relief valve when the sheet reaches a predetermined distance fromsaid stack, releasable means to hold said valve open while said footreturns to contact the next succeeding sheet in the stack, and meansoperated by said foot to release said last named means to cause the nextsucceeding sheet to adhere to said foot.

12. In a sheet feeding mechanism, a frame, a

pair of feeding rolls carried by said frame, a support for a stack ofsheets to be fed, a sheet separator, a rod on which the separator isadjustably mounted, an oscillatabie shaft, a pair of rock arms thereoncarrying said rod, means to rock the shaft to lift the separator fromthe stack, and means acting on said separator after it has moved upwarda predetermined distance to swing said separator toward said rolls.

13. In a sheet feeding mechanism, a frame, a pair of sheet feeding rollscarried by the frame, a-support for a stack of sheets to be fed, asuction sheet separating foot adapted to engage and raise the top sheetof said stack, a pivotally mounted member to which the foot is pivoted,a

guide acting on the foot between its pivot to said member and its freeend, to control the position of the mouth of the foot in the first partof its upward movement, and means for swinging the foot away from theguide and toward the feed rolls in the latter part of the upwardmovement of the foot.

FRANKLIN E. CURTIS.

